This data set contains hour-averaged magnetic field vectors from the Neubauer/Maier experiment on Helios 1. It provides 1-hr average values of the solar ecliptic X, Y, Z components of the magnetic field, in units of centi-gamma. Also available are the number of samples of each component used in the averaging. The location of the spacecraft is specified in terms of ecliptic longitude, heliographic latitude, and radial distance from sun. Data quality flags are also included.

This data set contains hour-averaged magnetic field vectors from the Ness/Mariani experiment on Helios 1. Each record contains time, magnetic field intensity and cartesian components in spacecraft-centered solar ecliptic coordinates, standard deviations, numbers of fine-scale points in the average, and an instrument mode indicator. It should be noted that the "average" mode, which was used a minority of the time and involved on-board averaging, may have incorrectly handled range changes caused by occasional significant changes in ambient field intensity. The data set had not been filtered for this effect upon delivery to NSSDC.

Data set records contain fluxes of protons in 5 energy
ranges (4-13, 13-27, 27-37, 37-51, >51 MeV), alpha particles in 6 energy ranges
(2-4, 4-13, 13-27, 27-37, 37-48, >48 MeV/n), and electrons in 2 ranges (0.3-0.8,
0.8-2.0 MeV). The fluxes are averaged over intervals of approximately one hour.
Each "data record" (having ending CR and/or LF) spans 4-5 hours and has 10
time-overlapping segments. Each segment has averaging start and stop times plus
words for 13 fluxes and words for the statistical uncertainties in the 13 fluxes.
However, most words in a given segment have fill values, such that good values
for a given flux (species and energy range) and its uncertainty appear only in
a minority of the segments. No spacecraft position information is included.
Data are from the E6 experiment on Helios 1.

This data set contains hourly averaged fluxes of protons measured by the GSFC Galactic and Solar Cosmic Ray experiment on Helios 1. The fixed length ASCII records have been reformatted from the binary format of the originally submitted data set (NSSDC ID 74-097A-08B). Each record contains the date and time in year, month, day, hour, minute, and second. The flux values and statistical errors are included for proton energy ranges of 3.3 - 21.6 MeV, 21.6 - 57 MeV, and above 57 MeV.

This directory includes hourly heliocentric coordinate data for the
Helios 1 spacecraft as extracted into the ASCII files HE1TRJyy.asc (yy
is the two-digit year) from the merged solar wind magnetic and plasma
data set in HELIOS_1/MGD_FREEMAN. All trajectory parameters except solar
ecliptic and heliographic inertial coordinates were taken from the
original merged dataset. The other parameters were computed and added
using the code HELTRJCON in the MGD_FREEMAN directory. Source routines
for coordinate conversions in this code were provided by R. Parthasarathy
of the Satellite Situation Center at NSSDC. The code READHEL in
MGD_FREEMAN was used to read the archived datasets into an intermediate
format for input to HELTRJCON. Code HELTRJCN1 was used to correct the
solar ecliptic angles as of 6/14/94 (see Note 2 above). HELTRJCON was
also corrected as of this date.
Data Parameter Description:
NY - YEAR OF THE DATA INTERVAL (LAST TWO DIGITS ONLY).
ND - DAY OF THE DATA INTERVAL FROM THE FIRST DAY OF THE ABOVE YEAR,
JAN. 1= DAY 1.
NH - HOUR OF THE DAY OF THE DATA INTERVAL.
NCARROT - CARRINGTON ROTATION NUMBER AS SEEN BY AN EARTH BASED OBSERVER
AT THE START OF THE DATA INTERVAL.
SPAU - SPACECRAFT HELIOCENTRIC DISTANCE IN ASTRONOMICAL UNITS.
SECLAT - SOLAR ECLIPTIC LATITUDE IN DEGREES
SECLON - SOLAR ECLIPTIC LONGITUDE IN DEGREES
HELLAT - SOLAR HELIOGRAPHIC LATITUDE IN DEGREES
HELLON - SOLAR HELIOGRAPHIC (CARRINGTON) LONGITUDE IN DEGREES
HILLON - SOLAR HELIOGRAPHIC INERTIAL LONGITUDE IN DEGREES WITH RESPECT TO
ASCENDING NODE OF SOLAR EQUATOR ON THE ECLIPTIC
ESSCSANG - EARTH-SUN-SPACECRAFT SEPARATION ANGLE (IN DEGREES, 0-360).
ICODE - DATA CODE: 1 MEANS PLASMA DATA ONLY ARE PRESENT FOR THAT HOURLY
INTERVAL; 2 MEANS MAGNETOMETER DATA ONLY; 3 MEANS BOTH PLASMA
AND MAGNETOMETER DATA PRESENT.
Note 1: The solar ecliptic coordinates are given with respect to true
equinox and ecliptic of date. The solar ascending node was located at
ecliptic longitude +74.367 degrees as of 1 Jan. 1900 at 1200 UT; this
longitude increases by 1.4 degrees/century.
Note 2: The solar ecliptic cordinates in this directory before 6/14/94 were
calculated incorrectly and have been corrected as of this date. The
heliographic angles are from the original source dataset and had no problems.

This data set contains orbital parameters for Helios 1: Helios-Sun distance, heliographic longitude from the ascending node, heliographic latitude, ecliptical longitude from the mean equinox, ecliptical longitude from the Earth-Sun line, ecliptical latitude, Helios - Earth distance,
and number of rotations of the Sun referred to Helios since launch.